Messages in this thread | | | Subject | Re: [PATCH v7 11/23] iommu/arm-smmu-v3: Maintain a SID->device structure | From | Robin Murphy <> | Date | Wed, 8 May 2019 15:05:47 +0100 |
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On 08/04/2019 13:18, Eric Auger wrote: > From: Jean-Philippe Brucker <jean-philippe.brucker@arm.com> > > When handling faults from the event or PRI queue, we need to find the > struct device associated to a SID. Add a rb_tree to keep track of SIDs.
Out of curiosity, have you looked at whether an xarray might now be a more efficient option for this?
Robin.
> Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com> > --- > drivers/iommu/arm-smmu-v3.c | 136 ++++++++++++++++++++++++++++++++++-- > 1 file changed, 132 insertions(+), 4 deletions(-) > > diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c > index ff998c967a0a..21d027695181 100644 > --- a/drivers/iommu/arm-smmu-v3.c > +++ b/drivers/iommu/arm-smmu-v3.c > @@ -588,6 +588,16 @@ struct arm_smmu_device { > > /* IOMMU core code handle */ > struct iommu_device iommu; > + > + struct rb_root streams; > + struct mutex streams_mutex; > + > +}; > + > +struct arm_smmu_stream { > + u32 id; > + struct arm_smmu_master_data *master; > + struct rb_node node; > }; > > /* SMMU private data for each master */ > @@ -597,6 +607,7 @@ struct arm_smmu_master_data { > > struct arm_smmu_domain *domain; > struct list_head list; /* domain->devices */ > + struct arm_smmu_stream *streams; > > struct device *dev; > }; > @@ -1243,6 +1254,32 @@ static int arm_smmu_init_l2_strtab(struct arm_smmu_device *smmu, u32 sid) > return 0; > } > > +__maybe_unused > +static struct arm_smmu_master_data * > +arm_smmu_find_master(struct arm_smmu_device *smmu, u32 sid) > +{ > + struct rb_node *node; > + struct arm_smmu_stream *stream; > + struct arm_smmu_master_data *master = NULL; > + > + mutex_lock(&smmu->streams_mutex); > + node = smmu->streams.rb_node; > + while (node) { > + stream = rb_entry(node, struct arm_smmu_stream, node); > + if (stream->id < sid) { > + node = node->rb_right; > + } else if (stream->id > sid) { > + node = node->rb_left; > + } else { > + master = stream->master; > + break; > + } > + } > + mutex_unlock(&smmu->streams_mutex); > + > + return master; > +} > + > /* IRQ and event handlers */ > static irqreturn_t arm_smmu_evtq_thread(int irq, void *dev) > { > @@ -1881,6 +1918,71 @@ static bool arm_smmu_sid_in_range(struct arm_smmu_device *smmu, u32 sid) > return sid < limit; > } > > +static int arm_smmu_insert_master(struct arm_smmu_device *smmu, > + struct arm_smmu_master_data *master) > +{ > + int i; > + int ret = 0; > + struct arm_smmu_stream *new_stream, *cur_stream; > + struct rb_node **new_node, *parent_node = NULL; > + struct iommu_fwspec *fwspec = master->dev->iommu_fwspec; > + > + master->streams = kcalloc(fwspec->num_ids, > + sizeof(struct arm_smmu_stream), GFP_KERNEL); > + if (!master->streams) > + return -ENOMEM; > + > + mutex_lock(&smmu->streams_mutex); > + for (i = 0; i < fwspec->num_ids && !ret; i++) { > + new_stream = &master->streams[i]; > + new_stream->id = fwspec->ids[i]; > + new_stream->master = master; > + > + new_node = &(smmu->streams.rb_node); > + while (*new_node) { > + cur_stream = rb_entry(*new_node, struct arm_smmu_stream, > + node); > + parent_node = *new_node; > + if (cur_stream->id > new_stream->id) { > + new_node = &((*new_node)->rb_left); > + } else if (cur_stream->id < new_stream->id) { > + new_node = &((*new_node)->rb_right); > + } else { > + dev_warn(master->dev, > + "stream %u already in tree\n", > + cur_stream->id); > + ret = -EINVAL; > + break; > + } > + } > + > + if (!ret) { > + rb_link_node(&new_stream->node, parent_node, new_node); > + rb_insert_color(&new_stream->node, &smmu->streams); > + } > + } > + mutex_unlock(&smmu->streams_mutex); > + > + return ret; > +} > + > +static void arm_smmu_remove_master(struct arm_smmu_device *smmu, > + struct arm_smmu_master_data *master) > +{ > + int i; > + struct iommu_fwspec *fwspec = master->dev->iommu_fwspec; > + > + if (!master->streams) > + return; > + > + mutex_lock(&smmu->streams_mutex); > + for (i = 0; i < fwspec->num_ids; i++) > + rb_erase(&master->streams[i].node, &smmu->streams); > + mutex_unlock(&smmu->streams_mutex); > + > + kfree(master->streams); > +} > + > static struct iommu_ops arm_smmu_ops; > > static int arm_smmu_add_device(struct device *dev) > @@ -1929,13 +2031,35 @@ static int arm_smmu_add_device(struct device *dev) > } > } > > + ret = iommu_device_link(&smmu->iommu, dev); > + if (ret) > + goto err_free_master; > + > + ret = arm_smmu_insert_master(smmu, master); > + if (ret) > + goto err_unlink; > + > group = iommu_group_get_for_dev(dev); > - if (!IS_ERR(group)) { > - iommu_group_put(group); > - iommu_device_link(&smmu->iommu, dev); > + if (IS_ERR(group)) { > + ret = PTR_ERR(group); > + goto err_remove_master; > } > > - return PTR_ERR_OR_ZERO(group); > + iommu_group_put(group); > + > + return 0; > + > +err_remove_master: > + arm_smmu_remove_master(smmu, master); > + > +err_unlink: > + iommu_device_unlink(&smmu->iommu, dev); > + > +err_free_master: > + kfree(master); > + fwspec->iommu_priv = NULL; > + > + return ret; > } > > static void arm_smmu_remove_device(struct device *dev) > @@ -1952,6 +2076,7 @@ static void arm_smmu_remove_device(struct device *dev) > if (master && master->ste.assigned) > arm_smmu_detach_dev(dev); > iommu_group_remove_device(dev); > + arm_smmu_remove_master(smmu, master); > iommu_device_unlink(&smmu->iommu, dev); > kfree(master); > iommu_fwspec_free(dev); > @@ -2265,6 +2390,9 @@ static int arm_smmu_init_structures(struct arm_smmu_device *smmu) > { > int ret; > > + mutex_init(&smmu->streams_mutex); > + smmu->streams = RB_ROOT; > + > ret = arm_smmu_init_queues(smmu); > if (ret) > return ret; >
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